Electric hoisting system.



. PATENTED MAR. 26, 1907. J. D. IHLDER & R. W. SCOTT.

ELECTRIC HOISTING SYSTEM.

APPLICATION FILED JULY 29, 1905.

Z SHEETS-SHEET 1.

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' ATTORNEY WITNESSES:

1 PATENTED MAR. 26, 1907. J. D. IHLDER & R. W. SCOTT.

ELECTRIC HOISTING SYSTEM.

APPLICATION FILED JULY 29, 1905.

2 SHEETS-SHEET '2.

' II'UNITEI) srA'rns PATENT orrron;

Jonson-moan, or r w YORK, N. Y., AND RUMSEY W. SCOTT, or WASH- l:INGTON, DISTRICT OF COLUMBIA, ASSIGNORS TO OTIS ELEVATOR COMPANY, OFJERSEY- OITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTRIC HoisTme SYSTEM.

Patented March 26, 1907.

To all whom it may concern.-

' i Beit'known. that We, JOHN D. IHLDER, residingat New York city, inthe county of New Yorkand State of New York, and Runsny'w. Scor'r,residing at Washington, .District'of- Columbia, citizens of the UnitedStates, have jointly invented a new and useful Improvement in ElectricHoisting Systems, of which the following is a specification.

Our invention relates to those classes of hoisting apparatus which areelectrically operated, and has for its object the provision of aself-locking device near the upper limit of travel'of a car or carrierfor preventing the carjromfalling should the hoisting apparatusbecomeino erative, and electric means for actuating said self-locking deviceso that the car ma descend when desired, in combination' wit means forautomatically slowing down the speed of the car or carrier as itapproaches its upper limit of travel and for electrically holding thesame at that point through the action of an electric motor connected todrive the hoisting apparatus, and

for automatically slowing down said car in accordance with the load asit approaches its lower limit of travel.

\Other objects will appear hereinafter, the

novel combinations of parts being set forth in the claims.

In the accompanying drawings, Figure- 1 represents diagrammatically themotor-controlling apparatus and latch device embodied 1n our invention,and Fig. 2 represents an electric elevator system to illustrate anapplication of the invention.

Referring now articularly to Fig. 1, 1O designates a mainine switchconnecting the apparatus to the source of current-supply, (designated bythe characters and 20 designates a manually-operable switch. 30 is amagnetic locking device, and 26 designates an electromagnet which servesto c0mplete, a circuit through the hoisting-motor. 40 designates what wecall the load-magnet and serves to operate the movable contacts 42, 43,and 44, and thus control the resistances 37, 38, and .39. is anelectronmgnet controlling the resistance :32. is an accelerating-magnetwhich controls the various: movable contacts shown directly under it,these contacts being connected to the several resistances 33, 34, 35,&c. 47 designates an electromagnet controllingthe movable contact 48. isthe hoisting-mo tor, whose field is shown at 61, 62 being themotor-armature and 63 and 64 the armaturebrushes. is an automaticstop-motion switch and comprises a number of circularlysha edcontact-strips, such as 79, 91, 93, &c., an insulating-pieces 80, 81',92, 97, 98, &c. These are mounted on some insulating material, such asslate, and the whole is rotata- -bly mounted and is preferably connectedby The main switch 10 being in the position shown on the drawingsthatis, closed-the contact-strip 14 of the switch 20 will be con nected totheor negative main of the supply of current. piece 15 is always incontact with the stri '14 and is pivoted at the center 18, about w ichit may be moved by means of the arm 1 6 and handle '17. If the latter bemoved toward The segmental contact? the left, the contact-piece 15 willengage the contacts 1 and 2. Now 1 and 2 are connected by wires to thecontact-brushes $4 and 85, respectively, on the automatic stopmotionswitch 75. The brushes l-"and 85 are shown connectedto the brushes 86and 87 by the contact-strips 91? and 9 5, res ect-ively. The brush 86 isone terminal 0 the circuit for the brake-magnet 66. The other terminalof this magnet is connected by wires 73 and 11 to the or positive main.The brake-magnet 66 will now receive current and by means of the toggle68 will overcome the action of the spring 67, and thus move thebrake-bands 71 from the frictionpulley 69, allowing the latter to turnfreely. Atthe same timethe brush 87 s connected to the brush 85 bycontact-strip 95, and since brush 87 is connected to one terminal of'themagnet 26, whose other terminal 18 connected to the positi e-mam by wire11, the

motor will now start at slow speed, the brake having been released. Onfurther moving the handle 17 to the left the contact-piece will engagethe fixed contact This con- "tact is connected by wire to the brush 83,which is in electrical connection with the brush 88 throughcontact-strip 94. New 88 is connected to one terminal. of the magnet 45,whose other terminal is connected by wire 29 to the positive main whenthe contacts 27 have been operated. 45 will now be energizcrl, beingconnected across the mains, and the contacts 46 will be broughttogether. This operation will cause the resistance 32 to beSllOIlZrClIClliliGtl and the motor will now receive more current and runat a faster speed. The next operation of the switch is when the handle17 has been placed in its extreme left-hand position, energizing thecontact 4, which is connected, through the automatic stop-motion switch75, to one terminal of the aecelcrating-magnet 50. of this magnet 50 isconnected by wires 1'01 and 49 to one of the armature-brushes. Thus themagnet 50 is connected across the motorarmature and will operateautomatically to cut out or short-circuit the accelerating resistances33, 34, 35, and 36 consecutively in.

a well-known way depending upon the load on the motor.

One terminal of the magnet 47 is connected to the insulated contact 55and as soon as the magnet 54 has been operated by the magnet 50, 55 willengage 56, which has already been connected to the positive line throughwires 31 29, contacts 27, and Wire 11. The other terminal of magnet 47is connected, through the. automatic stop-motion swatch andoperating-switch 20,- to the wire 13, which is connected to the negativemain. 'lhcrcl'orc soon as the contact 55 engages contact 56 the magnet47 will be energized and operate contacts 48, causing the resistance 36"to be cut out or short-circuilcd. The motor-armature now receivescurrcnt at the lincpotential and can run up to full speed to drive thecar or carrier iii an upward direction. The automatic stop-moiion switch75 has in the meanwhile slowly revolved in a clockwise direction, beingdrivca, as before pointed out, by the hoisting machinery. As the car orcarrier approaches its uppcr limit the first operation of the switch 75will be when the contact-brush 82 runs onto the insulating-piece 9.).This will cause the magnets 50 and 47 to become dccncrgizcd, since theircurrcnt supply is inter- The other terminal 2 6, 40, 45, 50, and-47.

rupted at the brush 82. 1 This will operate to replace the resistances33, 34, 35, 36,and 36 back into the armature-circuit, which will causethe motor to immediately slow down.

Very shortly after this operation has taken place the contact-brush 83runs onto the insulating-piece 98. This causes the magnet to the circuit45 to-be broken, causing to drop its contact and replace the resistance32 in the armature-circuit, causing the motor to 1 run at a very slowspeed, the current to the motor-armature being very materially reducedon account of having replaced all of the starting resistance in serieswith the armature. The car or carrier is now brought up against thebuffer at the top of its runthat is, to the" desired upward limit of itstravel. The current which is still being applied to the mot-or is ofsuflicient strength to cause the load to be held against the buffer, butit is not sutficient to injure the motor armature.

In Fig. 2 we have illustrated more or less diagrammatically an elevator"system including a hoisting-drum 103, hoisting-cables 100,counterweight 1V, and a car C. The floorcontroller is shown connectedby-sprockets and sprocket-chain to the hoisting-drum.

On the controller-board 105 are mounted the main-line switch 10 and theelectromagnets The latch device 30 may have its fixed pivot of courseconnected to some rigid support in any well-known manner. At or near theupper limit of the travel of the car or carrier, as shown 1n Fig.

2,is.a self-locking device 30, which is so constructed that it allows amovement 'ofsome, part, as 25, of the carrieror car C a short d1stancepast the latch 24, but will prevent or hold the carrier from movement ina down-' ward direction past said latch until said latch is released bymeans of the electromag.

net 102. This self-locking mechanism, there;

fore,-constitutes a safety device to prevent the carrier from fallingordescending below the same when not desired if the hoistingcablesshould break or the electrical holding means become inoperative,

When it is desired to lower the car or carrier, the switch-handle 17 isbrought back to its central position, as shown on the drawings. Thiswill cause the brake to be applied, as the circuit to the magnet 66 isbroken at the contact Furthermore, the circuit of magnet 26 isinterrupted at the contact 2, and there fore the contacts 27 are opened.The current to the motor is thus cut oil, and the carrier could descendby reason of its own load, but is held from doing so by the latch 24.and the brake; On moving the handle 17 to the right, however, thecontact 15 will engage with the fixed contactsfi and. 6. A circuit willthen be closed through the magnet 102 from the positive main, throughwires 11. and

1t), contact 5, segment 15, wire 13 to the lingerie I main. will causethe magnet 1'02 tolbe energized, and'the latch will be Iribvedout of thepath of the part' 25 by means of the connection between saidelectroniagnet and latch. The carrier. is now has to descend by reasonofits own weight.

'- We'will'now describe our automatic means for slowing'down themovement; of the carrier'and stopping same. at its lower limit oftravel; At t 15 made connection'with the contact 5 it was broughtjintoelectrical connection with the contact 6., thus short-cirouitingthe motor-armature tluough'tl'lesame resistances used to accelerate themotor in starting the carrier in its upward movement and also additionalre sistances 37, 38, and 39. On further movement of the handle;17 to theright thesegment will engage the fixed contacts 7 and 8. Contact 7 isconnected to brush-7 6 on the automatic stop-motion switch. Contact 8 is.connectedby brush 90 with COIliifiCli-Slilll') 91 and brush 86 totheelectromagnet 66.0f the brake. -fhds thebrake-magnet will be at onceenergized, and the brake released, allowmg the motor lt'o be revolvedbackward by the load. Since themotor has its field 61 connected acrossthe line by wires 11 and 12, the "same will be fully excited, and thearma-.

turebeingdriven by the load will generate a carrier descends theautomatic stop-motion switch 75 will be: driven in a counter-clock-.wise direction by'the' hoisting machinery. As the car approachesjthelower limit of its I travel the slowdown operation is automatic- =40- Aswitch. The first change will be the c0nnec ally controlled by means ofsaid stop-motion tion of the fast speed magnet in shunt to theresistances 37,38, and 39. This shuntcircuit ma be traced from the wire-29 to and through the magnet 45, brush 88, strip 94, brushes 51 and76, contact 7, segment 15 to the other side of the load-magnetresistances. The load-magnet resistances combined are preferably greaterthan the combined accelerating'resistances, so that the energization ofthe magnet 45 depends on the potential across the load-magnetresistances. This potential varies directly as the speed of the car. Ifthe speed be too great, this potential rises to such a point that magnet45 is energized and short-circuits the resistance 32 .by closing-thecontacts 46. The resistance in the armature-circuit being thusdecreased, more current can flow, and the electrod namio braking actionwill be increased. car will therefore run at a reduced speed. Theautomatic stop-motion switch has now revolved, to such a' position thatthe-contactbrush 76 runs onto the contact-strip 78, ,to"hold said new atthe upper. limit :of its which is connected to one terminal of thel esame time that the segment l ad-magnetAO by the contact-brush 77 and thecircuit represented bybroken lines. The":

other terminal ofthe load-magnet is connected to the armature-brush 63.It will be seen that the load-magnet is now connected across or inshunt, to the motor-armature, and it the speed of the motor, to closemore or less of its contacts 42, 43, and 44, which operate to cut outo'rshort-circuit the load resistance in a well-known Way and acting tofurther slow down the motor in proportion to the load.

'will be energized to a degree depending upon I The next operation ofthe automatic stopmotion switch is when the insulating-piece 92 engagesthe contact-brush 90. This will interrupt all current-supply to thebrake-magnet 66,. and the the car at the bottom of its travel.

In reviewing the operation of the system brake will, be applied to stopit will be seen that when it is desired to raise a load the brake isfirst raised and current admitted to the motorthrough the startingresistance. Then a portion of the. starting resistance isshort-circuited, which causes a. 0 somewhat higher speed. Then-magnetsare e energized .to automatically short-circuit the remaining resistancein proportion. tothe load. I Asthe top of the'run is reachedfthe currentto, the motor is automatically reducedtosuch an amount as will benecessary to bring the load gen'tl againstthebuffer at, f

the, brake being j heldoff, At the same time a lockjlngfdevice I00movement, after which the brake maybe l the top'and hold it,,t ere,

effectually prevents any possible ownward applied by bringing thesegment 15 back to central position.

To lower the can the brake.

is first lifted and the locking device, released. I

The motor isthen turnedbackward by the load and becomes a dynamo,generating current through thc'st arting resistance and load resistancewhich are together in series with the motor-armature. I Toward the lowerend;

of travel a portion of the. starting resistance may be shoqt-circuited,depending on the speed of the car, and shortly afterward a.

magnet is shunted "across the armature, which operates to cutout theload resistance in proportion to the speed and load of. the descendingcar, and finally the brake is applied to stop the car.

. Without limiting ourselves to the precise construction or details andarrangement of parts as herein shown, but reserving the right to makesuch changes therein as' iallwithin the spirit andscope of ourinvention,

What we claim, and desire to be protected by Letters Patent, is+ Y 1.The combination a car,'of hoisting means therefor,-'an electric motorfor operatmg said. hoistrng means, means for causing the motor actingthrough said hoistingmeans from falling, and means for electricallyactuating said safety device so that the car may descend when desired.

2. The combination with a car, of means for hoisting said car, astationary device for preventing said car from descending, and electricmeans for releasing said device so that th" car may descnd when desired.

3. The combination with a car, of means for hoisting said car, aself-locking device permitting free movement of the car in an upwarddirection but preventing the car from'descending, and electric means forunlocking said locking device so that the car may descend.

4. The combination with a car, of means for hoisting said car, a catchnormally in the ath of a part of the car, and electromechanreal meansfor actuating said catch, so con-' structed and arranged that the carmay have a free upward movementgbut is stopped in its downward movementunless .or until the catch is actuated.

5. The combination with a car, of operating means for the same, a catchfor preventing movement of the car in one direction but permitting freemovement in the other direction, an el'ectroresponsive device, andconnections between said electroresponsive de vice and said catchwhereby the catch can be so moved as to allow the car to move" freelypast the same in either direction when the electroresponsive device isenergized.

6. The combinationwith a car, of hoisting means for the same, a catchfor preventing descent of-the car but allowing free upward movementthereof, electromechanical means for operating said catch, and anelectric switch on the carrier closing a circuit to saidelectro'uiechanical means to actuate said catch so that the car maydescend.

7. The con'ibination with a car, of hoisting means for the same, aself-locking device for allowing free upward movement of said car butpreventing its downward movement, an electrores mnsivc device foroperating said self-locking device, and an electric-switch on the carfor controlling the circuit to said elent-nn'csponsive device, wherebywhen the latter is energized said self-locking device is actuatedso.th'at thc cm' may move down ward l v.

h. The co'mbilation with a car, of lllilhilllfl means for the same, ahoiding device having a part cxtcnding into the path of travcl ol' thecar for preventing ihc car from descending al'tcr lmving reached itsupper limit of travel. and electric means for actuating said holdingdevice so that the car may dcsccnd.

i). The combination with a car, of hoisting menus for the same, aself-locking dcvi'cc near the upper hunt of'travcl of said carforprcvcuting the same from descending, and an clcctrorcsponslvc devicecontrolled l'rom lhc ran for operating said sell-locking device.

10. The combination with a car, of hoist= ing means for the samecomprising an electric motor and main lines, a self-locking device nearthe upper limit of travel of said car for preventing the same fromdescending, an

electric switch in the car, and an electromagnet arranged to be placedacross said mains and to actuate said self-locking device when energizedso that the car may descend.

11. The combination with a car, of hoist- .ing means for the same, meansfor automatically reducmg the speed of said car as the same approachesthe upper limit ofitstravel,

a self-locking device near said limit of travel,"

and-electric means controlled from the car for operating saidself-locking device, the aforesaid parts being so constructed andarranged that the car may be heldelectrically by said hoisting means atsaid upper limit safety device near the said upper limit of' travel forpreventing the car from falling, an electroresponsive device foractuating said safety device so that the car may descend \vhendesired,an electric switch for controlling the automatic slow-down means and forcontrolling said electroresponsive device the aforesaid parts being soconstructed and acranged that when the carreaches the top it shall beheld the e by said electric motor acting through the said hoistingmeans.

13. The combination with a car, of hoisting means for the same, meanscomprising a stop-motion switch arranged to be automatically rotated,for reducing the speed of said car as it approaches the upper limit ofits travel and for holding the car at. said limit, a safety device nearthe upper limit of travel of said car for catching the -:u' if it shouldfall, an clcctrorcsponsive device for operating said safety device, andmanually-operable switching mechanism for controlling the current tosaid automaticall v-rotatable switch and to said electroresponsivedevice.

ll. 'lhe combinal ion with a car, ol means for hoisling said car, anclectrhr, motor for driving said hoisting means, switching mechanismarranged lo be automatically rotated to control the circuits to saidmotor as the 'n r approaches its upper limit so that the lat- {or shallhe reduced inspcml but sufficient currcnl allowed to llow through themotor to enable the same to cause the car to be held at its upper limitol" travel, a self-locking device IlC near the said upper limit soconstructed and.

as it approaches its upper limit of travel, the

.fore stop mg as said car approaches its lower car may move downwardlywhen desired, and circuits and connections, for gradually reduce amanually-operable switching device aring the speed of the car as itapproadhesits ranged to close circuits to said automatic upper limit andcause the motortd hold said switching mechanism when in one position Icar at that limit and for automatically IGClllG-S 5 and to close thecircuit to said electromagnet when in another position. 15. Thecombination with a car, of means for hoisting same, an electric motorfor driving said hoisting means, means comprising circuits andconnections for automatically and gradually reducing the speed of thecar said circuits and connections being so constructed and arranged thatthe car shall be held at its upper limit by said motor acting throughsaid hoisting means, means for auto matically reducing the speed of thecar belimit an varying such re notion of speed in accordance with theload, and a manuallyoperable switch for controlling when in oneposition-current to said automatic means for reducing the speed of thecar as it approaches its upper limit and for controlling when in anot erposition current to the lower-limit automatic means for slowing down thespeed ofthe car. l

' 16. The combination with a car, of means for hoisting same, anelectric motor for driving said hoisting means; means, comprising ingthe speed of the car as it approaches its rying such reduction of speedin accordance with the load, means for stopping the car at its lowerlimit of travel, a safety device near the upper limit for'catching orholding the car should the hoisting means become inoperative, anelectroresponsive device for actuating said safety device so that thecar may controlling when in one position the upperlimit slow-down meansand when in another position closing the circuit to saidelcctroresponsive device and controlling the lower' limit slow-downmeans.

In testimony whereof we have signed our names to this specification inthe presence of the subscribing witnesses. j

JOHN DIIH'LDER. nuMsnY w. sco'r'r;

Witnesses for Ihlder CHARLES M. N ssan,

C. BLINN- Witnesses for Scott:

J, E. WILSON, V

an automatically-rotatable limit-switch and GEORGE -J, Jonnsron.

lower limit by reason of its own load and ya descend, and amanually-operable switch for-

